Coolant poluted with tap water

[Gilles]

Originally Posted by thstone

Flush and refill with OEM coolant and distilled water. Simple and guaranteed no risk.

When I am flushing my cars, after draining the old fluid I fill the system with destilled water, run the engine until the thermostat opens, let it cool, drain (repeat..) until the water comes completely clean..

Thereafter, I fill it with a mix of the OEM coolant mixed with destilled water (never tap water).